Several things can indicate a problem: 1  Yellow or leaning flame (your flame should be blue) 2  Signs of corrosion, visible cracks or other instances of exterior wear and tear. 3  A smell like formaldehyde. 4  The presence of soot.
NSSF Rimfire Challenge. The NSSF Rimfire Challenge is a .22 rifle and pistol program created to introduce new people to the shooting sports and provide a pathway to shooting competition. The NSSF Rimfire Challenge can provide individuals or families with a fun and exciting first-time shooting experience. Shooting ranges can utilize the concept as a Second Round component to NSSF's First Shots program.
The first rimfire cartridges were .22s, but after the type became established many larger caliber rimfire cartridges were developed in the mid to late 19th Century. Some of these had a good run of popularity until they were superceded by the development of higher pressure centerfire ammunition. Calibers ranged from the .25 Short to the .58 Miller. Probably the best known of the larger caliber rimfires are the .25 Stevens, .32 Long, and .44 Henry Flat. The latter was the cartridge for which the seminal Henry and Winchester 1866 Yellow Boy lever action rifles were chambered.